Mihir Patkar

How you phrase your goal might have an effect on whether you complete it. Researchers say phrases starting with "I don't" are more effective for setting goals than those starting with "I can't".

The 2012 study, published in the Journal of Consumer Research, analyzed 120 students and their ability to resist eating chocolate. Those who said "I can't eat X" chose to eat the bar 61% of the time, as opposed to 36% from those who said "I don't eat X". The scientists write:

This research is based on the insight that the language we use to describe our choices serves as a feedback mechanism that either enhances or impedes our goal-directed behavior. Specifically, we investigate the influence of a linguistic element of self-talk, in which a refusal may be framed as "I don't" (vs. "I can't"), on resisting temptation and motivating goal-directed behavior.

Digital marketer CamMi Pham cited the study in a post that is worth reading for some quality insights on being productive, but if it's goal setting that you are specifically looking for, there is specific science for that too.